<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <script src="../js/jquery-1.11.3.js"></script>
    <script>
        $(function(){

            $('body').on('a1',function(e){
                e.stopPropagation()
                e.preventDefault();
                console.log(e.target);
            })

            $('*').trigger('a1');


        })
    </script>
</head>
<body>
<input type="text" id="username">
<a href="#"></a>


</body>
</html>